Photo Credit: Tyler Rooke

West Side

Today: Isolated showers. Mostly sunny, with a high near 85. Breezy, with an east northeast wind 9 to 18 mph, with gusts as high as 25 mph. Chance of precipitation is 20%.

Tonight: Isolated showers. Partly cloudy, with a low around 68. Breezy, with an east northeast wind 17 to 20 mph, with gusts as high as 28 mph. Chance of precipitation is 20%.

Tuesday: Isolated showers. Mostly sunny, with a high near 86. Breezy, with an east northeast wind 14 to 20 mph, with gusts as high as 28 mph. Chance of precipitation is 20%.

South Side

Today: Isolated showers after noon. Mostly sunny, with a high near 85. Calm wind becoming west around 6 mph. Chance of precipitation is 20%.

Tonight: Isolated showers before midnight. Partly cloudy, with a low around 67. Light and variable wind becoming northeast around 5 mph after midnight. Chance of precipitation is 20%.

Tuesday: Isolated showers after noon. Mostly sunny, with a high near 86. Northeast wind 5 to 11 mph becoming west southwest in the morning. Chance of precipitation is 20%.

North Shore

Today: Scattered showers, mainly before noon. Mostly sunny, with a high near 84. Windy, with an east wind 17 to 25 mph, with gusts as high as 36 mph. Chance of precipitation is 30%.

Tonight: Isolated showers. Partly cloudy, with a low around 67. Breezy, with an east wind 15 to 21 mph, with gusts as high as 29 mph. Chance of precipitation is 20%.

Tuesday: Scattered showers, mainly before noon. Mostly sunny, with a high near 84. Breezy, with an east wind 15 to 22 mph, with gusts as high as 31 mph. Chance of precipitation is 30%.

Central Maui

Today: Scattered showers, mainly before 1pm. Mostly sunny, with a high near 84. Breezy, with an east northeast wind 8 to 13 mph increasing to 17 to 22 mph in the afternoon. Winds could gust as high as 31 mph. Chance of precipitation is 30%.

Tonight: Scattered showers, mainly after 7pm. Mostly cloudy, with a low around 66. Breezy, with an east northeast wind 8 to 17 mph, with gusts as high as 24 mph. Chance of precipitation is 30%.

Tuesday: Scattered showers, mainly before 1pm. Mostly sunny, with a high near 84. Breezy, with a northeast wind 8 to 13 mph increasing to 16 to 21 mph in the afternoon. Winds could gust as high as 29 mph. Chance of precipitation is 30%.

Upcountry

Today: Isolated showers after 1pm. Mostly sunny, with a high near 71. Light and variable wind becoming west 5 to 7 mph in the afternoon. Chance of precipitation is 20%.

Tonight: Isolated showers before 1am. Partly cloudy, with a low around 55. Calm wind becoming southeast around 5 mph after midnight. Chance of precipitation is 20%.

Tuesday: Isolated showers after 1pm. Mostly sunny, with a high near 71. Light and variable wind becoming west around 6 mph in the afternoon. Chance of precipitation is 20%.

East Maui

Today: Scattered showers. Partly sunny, with a high near 82. East wind 8 to 14 mph, with gusts as high as 18 mph. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 63. East southeast wind 5 to 10 mph becoming south after midnight. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.

Tuesday: Scattered showers. Partly sunny, with a high near 82. South wind 6 to 13 mph becoming east northeast in the afternoon. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.

Lanai City

Today: Isolated showers after noon. Mostly sunny, with a high near 76. Breezy, with an east northeast wind 7 to 16 mph, with gusts as high as 22 mph. Chance of precipitation is 20%.

Tonight: Mostly clear, with a low around 63. East northeast wind 11 to 14 mph, with gusts as high as 18 mph.

Tuesday: Isolated showers after noon. Mostly sunny, with a high near 76. Breezy, with a northeast wind 11 to 21 mph, with gusts as high as 29 mph. Chance of precipitation is 20%.

Kaunakakai

Today: Mostly sunny, with a high near 83. Breezy, with an east northeast wind 9 to 15 mph, with gusts as high as 21 mph.

Tonight: Isolated showers before midnight. Partly cloudy, with a low around 71. East northeast wind 8 to 13 mph. Chance of precipitation is 20%.

Tuesday: Mostly sunny, with a high near 83. East northeast wind 8 to 13 mph.

Detailed Forecast

Synopsis

A broad high pressure ridge north of the state will keep moderate trade winds in the forecast into the weekend. Expect passing showers confined mostly to windward and mountain areas through the week. An upper level disturbance moves into the region on Friday, potentially increasing shower activity across the island chain into the weekend.

Discussion

Not much change this morning in the short range weather picture. This morning’s satellite imagery shows fairly stable clouds moving into the islands on the easterly trade wind flow. Local radar shows passing showers mainly over windward and mountain areas with some shower bands developing along lee-side island convergence plumes southwest and west of each island. A weak upper level low shows up in water vapor imagery just east of the Big Island.
A broad high pressure ridge will maintain strength north of the region producing moderate trade winds into the upcoming weekend. The upper soundings at 12Z this morning show subsidence inversion heights over Lihue Kauai around 6000 feet, and around 9000 feet over Hilo on the Big Island. These differences in trade wind inversion heights are related colder temperatures aloft near the weak upper low east of the Big Island, producing less stable conditions across the eastern side of the state. Forecast guidance shows cooler temperatures aloft (500 MB level) northeast of the Hawaiian Islands will persist through the week keeping passing windward and mountain showers in the forecast.

Aviation

Moderate easterly trade wind flow will continue across the state today and for the next several days. As a result, bands of scattered showers and clouds will generally favor the north and east sections of the islands throughout the forecast period as they are carried in on the trade wind flow.
Early this morning, AIRMET Sierra remains in effect for tempo mountain obscuration for eastern sections of the Big Island where latest radar and satellite imagery show the majority of showers and clouds have been focused for much of the night. Models suggest that some improvement may occur later this morning, however. Otherwise VFR conditions are expected to prevail today with only brief MVFR conditions in any passing showers.

Marine

Surface high pressure far northeast of the state will maintain moderate to locally strong trade winds this week. A Small Craft Advisory (SCA) is now in effect through early Tuesday morning for all of the typically windier waters adjacent to the islands of Maui County and the Big Island. This SCA may need to be extended for these same waters from Tuesday through mid-week based on the latest forecast.
The current moderate northwest swell will gradually lower from today through Wednesday. Surf will likely become nearly flat along most north facing shores from Thursday through next weekend. The current south swell will maintain surf heights near the May average along south facing shores through Tuesday. A new small, long period south swell arriving Wednesday is expected to persist through Friday. The moderate trade winds in the vicinity of, and upstream of the islands will likely produce surf heights near or slightly below the May average along east facing shores this week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Tuesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov